Atherton won in a time of three minutes 12.12 seconds
British riders won three downhill golds and two silvers at the Mountain Bike World Championships in Val di Sole.
Gee Atherton pipped compatriot Steve Peat to gold in the men's elite event, with a winning margin of 2.62 seconds.
His sister, Rachel Atherton, stormed to victory in the women's race, nearly 12 seconds clear of her nearest rival.
Josh Bryceland made it three golds for Britain, in the junior men's downhill, while GB's Liam Killeen took fourth in the men's elite cross country final.
Liam Killeen's mountain bike masterclass
Killeen finished behind a Swiss 1-2-3 of Christoph Sauser, Florian Vogel and Ralph Naef, and fellow Briton Oli Beckingsale crossed the line in tenth place.
Killeen and Beckingsale are both in the running to represent Great Britain at the Olympic mountain biking event in Beijing this August, with GB having earned two places in the men's cross-country.
In the junior event, Bryceland's team-mate Sam Dale was 7.51 seconds back in second place in Italy.
Bookmark with:
What are these?